Cicuta douglasii, the western water hemlock, is a very poisonous perennial plant in the family Apiaceae.
Description
thumb|The leaves of Cicuta douglasii (left), along with those of [[Conium maculatum (poison hemlock); both species are extremely poisonous.]]
The plant's roots are thick and tuberous, with many smaller tubers on the main one, allowing survival in wet conditions. The stem is tall with purplish spots. The inner tubers and stem bases can have horizontal chambers useful for identification. The leaves are alternate and compound pinnate; the secondary veins of the leaflets end at the bases instead of the tips of the teeth. The leaflets are long and wide, with jagged edges. In addition to sprouting new plants from seeds, rootstocks can also produce new plants in the fall from the basal meristem. When these detach the following spring, they may form a new plant.
thumb|alt=Cicuta douglasii, close-up showing part of leaf.|Leaf detail, showing distinctive venation (see text).
Distribution and habitat
Water hemlock is most abundant in British Columbia, Cicutoxin is a yellowish liquid that is prevalent in the roots. This unsaturated alcohol has a major impact on the central nervous system of animals. Early symptoms of cicutoxin poisoning include excessive salivation, frothing at the mouth, nervousness, and incoordination. These symptoms can progress to tremors, muscular weakness, seizures and respiratory failure. In addition to being extremely hazardous to humans, this plant has an enormous impact on animals. As little as 0.2–0.5% body weight for sheep, 0.1% body weight for cattle, 0.5% body weight for horses, and 0.3% body weight for swine can be lethal. Death can occur within fifteen minutes of ingesting the toxin. It is one of the first plants to emerge in springtime, and has a very appealing odor.